Monolithic hydrophobic cryogel columns for protein separation

L-proline determination by molecularly imprinted nanoparticles: A potential nanoscale tool for the diagnosis of metabolic disorders

Detecting and quantifying amino acids is vital in biochemical analyses, especially for diagnosing metabolic disorders. L-proline, among these amino acids, holds significant relevance for various metabolic disorders in living organisms, particularly in humans. hyperprolinemia arises when ineffective breakdown of L-proline occurs due to enzyme deficiencies, leading to its accumulation in the body and underscoring the need for precise monitoring. To address this challenge, molecular imprinting offers a reliable single-step technique for detecting target molecules like proteins, peptides, amino acids, or ions with high selectivity. Moreover, nanoparticles, with significant surface area-to-volume ratios, enable high-level mass transfer and binding kinetics, making them ideal for nano-scale sensitive applications. In this study, 2-hydroxyethyl methacrylate-based molecularly imprinted nanoparticles were synthesized via mini-emulsion polymerization, combining the advantages of molecular imprinting technique and nanoparticles for the specific recognition of L-proline, and were well-characterized by Scanning Electron Microscopy, zeta-sizer particle size analysis, and Fourier Transform Infrared Spectroscopy. Based on zeta-sizer analysis, the estimated diameters of L-proline-imprinted and non-imprinted nanoparticles (Pro-MIPs and NIPs) were determined to be approximately 27.51 nm and 20.66 nm, respectively. The adsorption of L-proline onto nanoparticles from aqueous solutions was investigated in a batch system, and the maximum L-proline adsorption capacity was determined to be 26.58 mg/g for Pro-MIPs and 4.65 mg/g for and NIPs. The selectivity of Pro-MIPs was assessed using Liquid Chromatography-Tandem Mass Spectrometry, even in human serum and in the presence of competing molecules (L-histidine and L-phenylalanine). Additionally, Pro-MIPs maintained their adsorption capacity through up to 10 adsorption-desorption cycles without significant decrease.

Surface functionalized cryogels - characterization methods, recent progress in preparation and application

Cryogels are polymeric materials with a sponge-like microstructure and have attracted significant attention in recent decades. Research has focused on their composition, fabrication techniques, characterization methods as well as potential or existing fields of applications. The use of functional precursors or functionalizing ligands enables the preparation of cryogels with desired properties such as biocompatibility or responsivity. They can also exhibit adsorptive properties or can be used for catalytical purposes. Although a very brief overview about several functional (macro-)monomers and functionalizing ligands has been provided by previous reviewers for certain cryogel applications, so far there has been no particular focus on the evaluation of the functionalization success and the characterization methods used. This review will provide a comprehensive overview of different characterization methods most recently used for the evaluation of cryogel functionalization. Furthermore, new functional (macro-)monomers and subsequent cryogel functionalization strategies are discussed, based on synthetic polymers, biopolymers and a combination of both. This review highlights the importance of the functionalization aspect in cryogel research in order to produce materials with tailored properties for certain applications.

Enhanced invertase binding from baker's yeast via cryogels included boronic acids

Invertase, an industrially significant glycoenzyme, was purified from baker's yeast using poly (2-Hydroxyethyl methacrylate) [PHema-Pba] cryogels functionalized with boronic acid. At subzero temperatures, PHema-Pba cryogels were synthesized and characterized using swelling tests, scanning electron microscopy, and Fourier-transform infrared spectroscopy. The surface area of the PHema-Pba cryogels was 14 m2/g with a swelling ratio of 88.3% and macroporosity of 72%. The interconnected macropores of PHema-Pba cryogels were shown via scanning electron microscopy. Invertase binding capacity of PHema-Pba cryogel was evaluated by binding studies in different pH, temperature, and interaction time conditions and the maximum Invertase binding of PHema-Pba cryogel was found as 15.2 mg/g. and 23.7 fold Invertase purification was achieved from baker's yeast using PHema-Pba cryogels. The results show that PHema-Pba cryogels have high Invertase binding capacity and may be used as an alternative method for enzyme purification via boronate affinity systems.

Sulfolane Crystal Templating: A One-Step and Tunable Polarity Approach for Self-Assembled Super-Macroporous Hydrophobic Monoliths

Freeze-casting (ice templating) is generally used to prepare super-macroporous materials. However, water solubility limits the application of freeze-casting in hydrophobic material fabrication. In the present work, inexpensive and low-toxic sulfolane was used as a novel crystallization-induced porogen (sulfolane crystal templating) to prepare super-macroporous hydrophobic monoliths (cryogels) with tunable polarity. The phase transition of sulfolane consisted of reversible processes in the liquid, semi-crystalline, and crystalline states. Because of the density change during phase transition, liquid sulfolane experienced a 16.4% volume shrinkage per unit mass. Thus, the cryogels obtained using the conventional freezing method contained obvious hollow-shaped defects. Furthermore, a novel route of pre-cooling, pre-crystallization, crystal growth, freezing, and thawing (PPCFT) was employed to prepare cryogels with defect-free macroscopic morphology and uniform pore structure. The as-obtained cryogels were composed of a super-macroporous structures and interconnected channels, and their porosity ranged between 85 and 97%. Moreover, the cryogels manifested good hydrophobicity (contact angle = 120-130°) and had absorption capacities greater than 10 g g^-1 for oils and organic liquids. The maximum absorption capacities of the resultant cryogels in dichloromethane, ethyl acetate, and liquid paraffin were 60.3, 35.8, and 15.2 g g^-1, respectively. Moreover, sulfolane could conveniently dissolve hydrophobic and hydrophilic monomers to generate amphiphilic cryogels (contact angle = 130-0°). Therefore, sulfolane crystal templating is a potential fabrication method for super-macroporous hydrophobic materials with tunable polarity.